Debugger UI: Removed debug language detection on mode change

It did more harm than good. Now, the auto detection is only done on
run control change - this is something that Creator could also remember.

src/plugins/debugger/debuggerrunner.cpp

@@ -498,6 +498,7 @@ void DebuggerRunControl::start()
         return;
     }
 
+    plugin()->activateDebugMode();
     DebuggerUISwitcher::instance()->aboutToStartDebugger();
 
     const QString message = tr("Starting debugger '%1' for tool chain '%2'...").
@@ -506,8 +507,6 @@ void DebuggerRunControl::start()
     plugin()->showMessage(DebuggerSettings::instance()->dump(), LogDebug);
     plugin()->runControlStarted(this);
 
-    plugin()->activateDebugMode();
-
     engine()->startDebugger(this);
     m_running = true;
     emit addToOutputWindowInline(this, tr("Debugging starts"), false);